You could make a warrior character and focus on the fatality skill: get it up to fifteen and you can end the fight with one blow when his health drops to fifty percent. He won't have used his healing spell by then (I think).
I was just thinking "Hey, maybe this would be a good time to try out Fatality!" With Bleed, a maxed Expertise, and some luck finding a level 10 damage enchantment in the marketplace, and this shouldn't take too long.
